The following disclosure relates generally to aircraft landing gear assemblies and, more particularly, to aircraft landing gear assemblies having multiple deployed static positions for accommodating different aircraft configurations.
Conventional land-based aircraft generally have some form of landing gear for taking off and landing. On many aircraft, the landing gears are retractable after taking off to reduce drag during flight. The tricycle configuration is a typical landing gear configuration that includes a steerable nose landing gear assembly (xe2x80x9cnose gearxe2x80x9d) and two main landing gear assemblies (xe2x80x9cmain gearsxe2x80x9d). The nose gear is positioned under a forward portion of the fuselage and each of the main gears is positioned under a wing. To ensure stability when on the ground, the nose gear is typically positioned forward of the center of gravity (xe2x80x9cCGxe2x80x9d) of the aircraft, and the main gears are typically positioned aft of the CG. In addition, because the main gears are generally configured to carry most of the ground loads, the main gears are typically positioned closer to the CG than the nose gear.
Changes to the structural configuration of an aircraft may require a reevaluation of the landing gear positions relative to the CG. For example, an aircraft manufacturer will often stretch the fuselage of a particular aircraft configuration to increase its passenger capacity. On a conventional aircraft configuration, the wings are mounted to a mid-portion of the fuselage, and the fuselage can be extended both fore and aft of the CG so that the CG does not move appreciably. In this situation, the main gears may not have to be repositioned to maintain the desired weight distribution between the nose gear and the main gears. Thus, by maintaining the CG position, an aircraft manufacturer is able to use the same wing and main gear configuration for both baseline and stretch versions of an aircraft. This is a significant benefit because the costs associated with designing and manufacturing multiple wing and main gear configurations can be substantial.
However, on some aircraft configurations, such as those having the wing mounted to an aft-portion of the fuselage, the fuselage must be extended forward of the wing to add passenger capacity. This tends to move the CG of the aircraft forward. To maintain the desired weight distribution between the nose gear and the main gears in this situation, the main gears should also move forward. Repositioning of the main gears in this manner can require a major redesign of the wing structure that supports the main gears, as well as a repositioning of the wheel wells that receive the main gears in their retracted positions.
The present invention is directed to aircraft landing gear assemblies, such as aircraft landing gear assemblies having multiple deployed static positions for use with different aircraft configurations having common or at least generally similar wing configurations. In one embodiment, a landing gear assembly usable with a wing includes a wheel truck and a strut configured to be pivotally connected between the wing and the wheel truck. In one aspect of this embodiment, the strut is configured to be connected to a first brace extending between the strut and the wing to position the wheel truck in a first deployed static position relative to the wing. In another aspect of this embodiment, the strut is further configured to be connected to a second brace extending between the strut and the wing to position the wheel truck in a second deployed static position relative to the wing different than the first deployed static position.
In another embodiment, the strut is configured to be pivotally connected to the first and second braces, the first and second braces being foldable drag braces. In one aspect of this embodiment, the first and second braces are interchangeably connectable to the strut at the same location on the main strut.
In a further aspect of this embodiment, the first and second braces are interchangeably connectable to the wing at the same location on the wing.
In a further embodiment, a method for manufacturing a second aircraft configuration derived from a first aircraft configuration is provided. In one aspect of this embodiment, the first aircraft configuration has a first CG location and the second aircraft configuration has a second CG location different than the first CG location. The first aircraft configuration can further have a first wing and a first landing gear assembly. The first wing can include a first pivot location and the first landing gear assembly can be pivotally connected to the first wing at the first pivot location. The first landing gear assembly can be configured to position a first wheel truck in a first deployed static position to support a portion of the weight of the first aircraft configuration.
In another aspect of this embodiment, the method for manufacturing the second aircraft includes providing a second wing, the second wing being at least generally similar to the first wing and having a second pivot location. The method can further include providing a second landing gear assembly, the second landing gear assembly configured to position a second wheel truck in a second deployed static position to support a portion of the weight of the second aircraft configuration. In a further aspect of this embodiment, the second deployed static position of the second wheel truck is different than the first deployed static position of the first wheel truck. The method can additionally include pivotally connecting the second landing gear assembly to the second wing at the second pivot location.